<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>
<body>
  <script>
    function Person(name, age) {
      this.name = name;
      this.age = age;
    }

    Person.prototype.eat = function () {
      console.log('Person  eat eat eat eat');
    };

    function Student(name, age, score) {
      Person.call(this, name, age);
      this.score = score;
    }

    Student.prototype = new Person();

    let stu = new Student('啊黑', 10, 80);
    console.log(stu);
    stu.eat();

    console.dir(Student);

  </script>
</body>
</html>